Method of making commutators, and blanks for use therein



March 12, 1935. 9 J. 1.. BONANNO 1,994,062

METHOD OF MAKING COMMUTATORS AND BLANKS FOR USE THEREIN Filed Feb. 12) 1951 INVENTOR Joseph Louis Bonanno A ATTORNEY Patented Mar. 12, 1935 1 UNITED STATES PATENT OFFICE METHOD OF MAKING COMMUTATOBS, AND BLANKS FOR USE THEREIN Joseph Louis -Bonanno, Forest Hills, N. Y. Application February 12, 1931, Serial No. 515,169

12 Claims. (01. 29-15554) 1 The present invention relates to methods of shown, is channel shaped in cross section havmaking commutators, and blanks for use there- .ing a web 10 and sides 11 and 12. It also has in and is more particularly: directed toward the a laterally extending flange 13 in the plane of manufacture of commutators for comparatively the web 10. small electric motors and kindred uses. The core of the commutator is a solid body of 5 As a preliminary stepin the manufacture of insulating material as indicatedat 15 in Figcommutators the present invention contemures 3, 6 and 7. It may be a solid block of in- 'plates the preparation of a special rolled or exsulating materialwith or without fabric reentruded section of a grade of copper suitable for forcement or may be molded to form or turned use in a commutator. This special section is oi to the desired shape from a larger body of in- 10 uniform cross section and indeterminate length. sulating material. In the 'small sized commuta- It has a channel shaped cross-section and may, tors this insulating body mayhave a central in addition, have a laterally extending flange hole 16 to accommodate the motor shaft while substantially in the 'plane of the web of the in the larger ones it may carry an insert in- 16 .channel. The outside width of the channeldedicated at 17. The ends of the insulating body termines theoverall length of the commutator. are preferably turned or undercut as indicated According to the invention this section-is cut at 18. v transversely to form it into segment forming In the preparation of a commutator the secelements connected together by a thin wall of tion shown in Figureji is subjected to a gang- I 20 the original section. A suitable length of the milling operation or to a shaping or breaching section thus cut is wrapped or bent about a operation so as to form transverse cuts in it as previously formed insulating core of such size indicated at 20. These cuts are regularly spaced as to fit inside the channel. The teeth or proand V-shaped as indicated. The material re- I jections now engage or embrace the ends of the maining in the channel walls 11. and 12 now cylindrical core,- and are then squeezed against becomes a' series of regularly spaced'tapered 25 this cylindrical core. The outside of the comteeth 21. The cuts are extended ahnost but not pletely formed commutator is then turned to all the way through the web as indicated at 22, true it and to remove the material which formthereby leaving a thin wall of metal which erly held the segments together. spaces the segment forming elements the same The accompanying drawing shows one form distance the parts were in the rolled section. v 30 in which the present invention may be embodied Either before or after the milling operation together with the steps employed in making up the section is passed through apunching mathe commutator. chine which punches the flange 13 'to form ar- In this drawing: maturelead connection lugs 23. These lugs are Figure 1 is an end view of a completed comarranged intermediate the notches 20 as will 35 mutator; be clear from Figure 5.

Figure 2 is a side elevational view of the The notched section, as indicated'in full lines same; in Figure 5, is then placed about a core 15 and. Figure 3 is a section taken on the line 3-3 of bent at the thin spots 22 so that the metal sec- 40 Figure 1; tion is wrapped or bent about the insulating 40 Figure 4 is a perspective view of a. rolled or body. The first step of such bending operation extruded section; is indicated in dot and dash lines. The teeth Figure 5 is a perspective view of a commutator 21 are then bent so as to be'close to one another v core with a transversely cut bar showing the but spaced as indicated in Figures 5 and 8. -The i method of assembling the bar and core; length of bar selected for making the commu- 45 Figures 6, and 7 are longitudinal sectional tator and the arrangement of the notches is views and end views, respectively, of an insusuch as to provide enough material to comlating core ofsmall size, and Q pletelywrap-about the insulating-core. The v Figure 8 is a perspective view of a partially joint between the ends of the section is 'indi-' completed commutator showing the turning of! cated at 24 in Figure 8. After this operation. 50 of the outside of the same. the core and metal envelope about it are placed Figure 4 shows a rolled or extruded section of in a press and the teeth 21 pressed inwardly as copper of a grade suitable foruse in commutaindicated in Figure 3. These teeth enter into tor manufacture. It is of uniform cross sec-. the undercuts 18 in the insulating body and se- 56 tion and indeterminate length and. at here surely lock the parts together.

. pendent commutator segments 8, each of which has tooth portion 21 gripping the ends of the insulating body. The design is such that-these segments are regularly spaced about; the commutator body and each is separated from the adjacent segment by an air. space formed without the use of mica strips or other inserted or applied means. r

Either before or after th'e turningoperation the lugs.23 may be bent outwardly to facilitate soldering them to the armature leads. They may all be dipped in a solder bathfif desired without injurin t nommutatorxstructure itself.

If one does not desire to provide this form of soldering lug the rolled section employed may be a simple channel, the web 13 having been omitted. In. this Ease the armature connections may be made in the usual manner by providing sawcuts in the ends of the commutator segments. v

It is obvious that the invention may be embodied in many 'forms and constructions within the scope of the claims, and I wish it to be understood that the particular forms shown are but two on the many forms. Various modifications and changes being possible, I do not otherwise limit myself in any way with respect thereto. f

I claim: Y

.1. A preformed strip for commutator manufacture comprising a channel shaped strip transversely notched to provide a plurality of channel shaped segment forming parts separated by readily bendable connecting parts extending the entire width of the strip and lengthwise of the segment forming parts whereby the segment forming parts may be brought close together to close upthe notches.

2. In commutator manufacture the method-of,

preparing a channel shaped copper strip of uniform cross section and indeterminate length for assembling on a cylindrical body, which consists in transversely cutting the flanges of the channel and a portionof the web of the channel to form the flanges into regularly spaced teeth for engaging the en of such body and to leave unsevered'a thinrtion of the web of the channel for the width of the channel, said portion being readily bendable to conform to the body.

3. .Inv commutator manufacture, the method yvhich consists in wrapping a transversely notched channelshaped metal bar about a cylindrical body of ,insulating material so that the notched side walls of the bar.'embrace the ends of the body, squeezing said side walls against the body and turning oil the periphery of the metal part to remove the material outside the notches I and form commutator segments.

7 4. In commutator manufacture, the method which consists in cutting away portions of the side walls-of a channel shaped bar and portions consists in transversely cutting a channel shaped metal bar to form notches in the sides oi. thechannel, bending the notched bar about a cylindrical body of insulating material with thesides of the channel receiving the ends of the body, securing said channel sides to the body, and removing the outer portions oi the web of the bar to form it into commutator segments.

6. The method of. making a commutator which consists in transversely cuttings. channel shaped metal bar to form notches in the sides of the channel, bending the notched bar about a cylindrical body of insulating material with the sidesof the channel receiving the ends of the body, bending the channel sides inwardly to cause them to grip the ends of the body, and removing the outerportions of the web of form it into commutator segments.

thebarto.

'1. The method of forming adjacent commu- ,tator segments out of the same .piece of metal which consists in forming the metal into a strip of channel shaped cross section cutting notches in the sides ofthe channel and part way through the channel web. without severing the web, applying said notched strip toa curved supporting body of a size'to be embraced by the channel, the strip bending about the midpoints between the teeth formed by the notches, then pressing the teeth against the body, and cutting away the portion of the channel web which was not included in the first cutting operation.

8. The method of making commutators, which sides of the bar into teeth and to form narrow grooves in the web of the bar between adjacent pairs of-teeth, bending the bar about a cylindrical body of insulating material having undercut ends so that the teeth vembrace the ends of the insulatingbody and the web or the bar assumes a cylindrical shape, pressing the teeth into the undercuts to lock the teeth to the insulating body, and turning-oif the web opposite the first mentioned cut to sever it into commutator segments and form a trued commutating surface.

9. The method of making cominutatofs, which consists in making regularly spaced transverse sides of the bar into tapered teeth and to form grooves in the web 01' the bar-between adjacent pairs of teeth, bending the bar about a cylindrical body of insulating material having undercut ends so that-the teeth embrace the ends of the insulating body and the web of the bar assumes a cylindrical shape, the'angle of taper of the v consists in making regularly spacedtransverse cutsinachannelshaped metalbartoformthe- ,cuts in a channel shaped metal bar to form the teeth being such that adjacent teeth are not brought into contact; pressing the teeth into the body, and turning oi! the web opposite the first mentioned cut to sever. it into commutator segments and form a truedcommutating surface. 10.. The method of making 'commutators, which consists in making regularly spaced V- shaped ,transverse: cuts in a channel shaped metal bar to form-the -sides of the bar into tapered teeth, separated by V'-shaped notches with the'narrowpart of the notches and to forming undercuts to lock the teeth to. the insulating groovesin the web bar between adjacent pairs ,of teeth, bending the bar about a cylindrical.

body of insulating material having undercutends so thatthe teeth embrace the ends of the insulating body and the web 01 the bar assumes a cylin'drical shape, the angle of taper of the teeth and the widthof up channel wallsbeing such t adiacentteeth are not brought into contact,

lindrical insulating body with the cut away portions adjacent the body and the segment forming parts otherwise out of contact, securing each segment forming part to the ends of the body, and then turning the cylindrical object thus formed to a smaller diameter so as'to cut away the integral connecting elements and disconnect the segment forming parts from one another and form gaps between adjacent segments, and so as to provide a true cylindrical commutator surface.

12 In commutator manufacture, the method which consists in forming a bar into a plurality of commutator segment forming parts by transversely cutting away portions of the bar to form transverse grooves and segment forming parts physically connected together by integral metal connecting elements extending across the bottoms of the grooves, bending the bar into cylindrical form with the unseverecl portions disposed about the surface of the cylinder and the adjacent segments forming parts otherwise out of contact, fixedly securing all the segment forming parts about an insulating body, and then turning of! the outer parts of the cylindrical object thus formed to. remove the connecting elements so that spaced segments are formed and so as toprovide a true cylindrical commutator surface. 20

JOSEPH LOUIS BONANNO. 

